JP2765264B2 - Ground drilling method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for perforating the ground while blowing air bubbles.

[0002]

2. Description of the Related Art In mountain tunnel construction and the like, drilling for loading blasting and drilling for burying rock bolts are performed. In this type of drilling work, a drill for drilling with a bit attached to the tip of a rod is attached to a rock drill, and rotation and percussion motion are transmitted to the bit to drill the ground by impact drilling. The generated debris is discharged from between the outer periphery of the drill and the hole. Conventionally, air or water is injected in parallel with the drilling operation to cool the drill, prevent dust, and promote the discharge of shear. However, there are the following problems.

[0003] In other words, when water is used, there are problems such as muddy soil and muddy scaffolding. In addition, the perforation walls of sandstone, horned rock, etc. are blocked by the impact of drilling and flushing water,
The drill was caught by jamming, and the work efficiency was reduced due to the inability to drill such as breakage of the drill. Also, when the air is increased, problems such as cooling and dust have occurred. In addition, the roughening of the perforated wall impairs the explosive loading operation, the blasting effect, and the locking of the bolt.

[0004] Therefore, it has been studied to use air bubbles for the purpose of preventing dust from being generated and preventing muddying and, at the same time, making the perforated wall self-supporting.
No. 4, JP-A-2-232496 (international classification:
E21C 7/06) and the like disclose a method and an apparatus in which air bubbles are ejected from the tip of a bit to form a hole while cutting chips into a slurry. However, these methods and apparatuses have the following problems.

[0005]

In other words, all of these pump the bubbles or a mixture of the bubbles and the compressed air into the elongated flow holes in the bit, but the bubbles become extremely viscous when they become bubbles. Therefore, it is difficult to pass through the flow holes, and a considerably high pressure is required for supplying the bubble forming material. However, many air compressors have low pressure,
Since the supply amount and discharge pressure of the material for forming the bubbles were small, the formation of the bubbles was insufficient and no effective effect was obtained.

The present invention has been made to solve the above-mentioned problems, and provides a method and an apparatus for piercing a ground in which a sufficient amount of air bubbles can be supplied from near the tip of a bit even if the air is fed at a low pressure. The purpose is to do.

[0007]

In order to achieve the above object, the present invention provides a method of piercing a ground, in which a gas-liquid two-phase fluid of a foaming agent solution and compressed air is pressure-fed to a bit end of a drill bit for drilling. The bubble is generated by bubbling the gas-liquid two-phase fluid near the tip of the bit, and the bubble is discharged from the tip of the bit.

[0008] In the present invention, a gas-liquid two-phase is formed in a flow hole formed inside a drill for drilling.
A compressed air supply device and a foaming agent solution supply device connected via a merging device for generating a fluid, and a porous resistor provided at the tip of the drill for drilling for foaming a gas-liquid two-phase fluid. ing.

[0009]

According to the above-described drilling method and apparatus, the foaming agent solution and the compressed air supplied through the merger into the hollow portion of the drill are drilled as a gas-liquid two-phase fluid, and are pressure-fed. Immediately before jetting from the tip of the bit, turbulence is generated by the porous resistor and foams to generate bubbles.

[0010]

1 shows a perforation apparatus according to the present invention. In the figure, a drill 2 for drilling provided at the tip of a rock drill 1 connects a plurality of relay rods 5 to a shank rod 3 connected to the rock drill 1 via a joint 4, and a cutting rod 5 at the forefront. The bit 6 is screwed and fixed to the tip of. The rock drilling machine 1 includes a motor 7 for rotationally driving the shank rod 3 and a hitting device 8 facing the rear end of the shank rod 3, and transmits rotation and percussion motion to the drill 2 for drilling.

At the center of the shank rod 3 and the relay rods 5, flow holes 3a, 5a are formed, and a swivel joint 9 is arranged on the outer periphery of the shank rod 3. This swivel joint 9 has
The hose 10 is connected, and a merging device 14 is connected to a base side of the hose 10. And in the merging device 14,
An air compressor 11 (compressed air supply) is connected via a flow control valve TA, and a foaming agent solution tank 12 (foaming agent supply) via a flow control valve TB and a pump P.

The foaming agent solution tank 12 contains a 1 to 3% aqueous solution of a foaming agent composed of a surfactant or the like, to which a small amount of a thickener is added to increase the viscosity of the foaming agent solution. I have.
The details of the merger 14 are shown in FIG. The merging device 14 shown in FIG. 1 includes a joint portion 14a to which the flow control valves TA and TB are connected, and a helical tube 14b, and converts the foaming agent solution and the compressed air into a gas-liquid two-phase fluid. The structure prevents the compressed air from leading when pressure-feeding.
In this case, in order to more reliably prevent the leading of the compressed air, the foaming agent solution and the compressed air are merged alternately by controlling the air compressor 11, the pump P, or the flow control valves TA and TB. What is necessary is just to send to the container 14.

The foaming agent solution and the compressed air are converted into a gas-liquid two-phase fluid by a merger 14, passed through a hose 10 and a swivel joint 9, and flow holes 3 a, 5 a formed in each rod 3, 5. Is supplied to the bit 6 in a state where it is easily foamed.

As shown in FIG. 3, the bit 6 has a drilling blade 6a integrally provided at the tip thereof. Inside the bit 6, a flow hole 6b having the same diameter communicating with the flow hole 5a is provided.
An expansion chamber 6c having a one-step diameter increase is formed continuously to this,
Further, the distal end side of the expansion chamber 6c is continuous with a small-diameter jet port 6d opening at the center of the cutting tool 6a.

Then, a jet port 6d extends from the tip of the expansion chamber 6c.
The inside is filled with a porous resistor 16 made of beads, fibers of metal or the like. Therefore, the gas-liquid two-phase fluid that has entered the bit 6 is foamed by the cross-sectional shape and the resistor 16 in accordance with the mixing ratio of the foaming agent solution and the compressed air, and corresponding bubbles are generated. The air bubbles are discharged to the outer perforation E1 side.

In this case, the viscosity of the foaming agent is as low as 10 to several hundred centipoise in the non-foamed state, but is several thousand to 10,000 centipoise in the foamed state even if the thickener is added. In addition, desired bubbles are generated by changing the mixing ratio of the gas-liquid two-phase fluid in accordance with the properties of the ground, and the generated bubbles are mixed with the drilling debris, and are discharged through the perforations E1 by excess air ejected with the bubbles. It is discharged to the face side. The discharged bubble and waste two-phase fluid loses fluidity and is disposed of as normal waste due to the addition of an antifoaming agent or the natural disappearance of bubbles.

[0017]

As has been described in detail in the above embodiments, the method and the apparatus for piercing the ground according to the present invention provide a foaming agent solution and a foaming agent solution supplied into a hollow portion of a drill for drilling through a merger. Compressed air is pressure-fed as a gas-liquid two-phase fluid and foams at the stage of discharging from the tip of the bit, so even if the pressure is low, a sufficient amount of air bubbles can be discharged to the perforated surface. This is suitable for preventing the generation of dust and preventing the formation of mud and at the same time for the self-support of the perforated wall.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outline of a ground drilling device according to the present invention.

FIG. 2 is an enlarged view of the merger of FIG.

FIG. 3 is an enlarged sectional view of a bit part in FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rock drill 2 drill for drilling 3 shank rod 5 relay rod 3a, 5a, 6b flow hole 6 bit 6a cutting tool 6c expansion chamber 6d spout 9 swivel joint 11 air compressor 12 foaming agent solution tank 14 merger 16 porous Resistor E1 perforation

Continuation of the front page (56) References JP-A-2-101284 (JP, A) JP-B-48-34317 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) E21C 7 / 06 E21B 21/14

Claims (2)

(57) [Claims] 1. A gas-liquid two-phase fluid of a foaming agent solution and compressed air is pressure-fed to a bit tip of a drill bit, and the gas-liquid two-phase fluid is foamed near the tip of the bit to generate air bubbles. And discharging the air bubbles from the tip of the bit. 2. A compressed air supply device and a foaming agent solution supply device connected to a flow hole formed inside a drill for drilling through a merger for generating a gas-liquid two-phase fluid, And a porous resistor provided at the tip of the drill and configured to foam a gas-liquid two-phase fluid .